牡荆素解离常数的测定  

Determination of the Dissociation Constant of Vitexin

作　　者：李晓亮[1] 张磊 牛海军[1] 李光辉 LI Xiaoliang;ZHANG Lei;NIU Haijun;LI Guanghui(Hefei Seven Star Pharmaceutical Science and Technology Co.,Ltd.,Hefei,Anhui,China 230088;Anhui Provincial Institute for Food and Drug Control,Hefei,Anhui,China 230031)

机构地区：[1]合肥七星医药科技有限公司,安徽合肥230088 [2]安徽省食品药品检验研究院,安徽合肥230031

出　　处：《中国药业》2020年第15期26-28,共3页China Pharmaceuticals

基　　金：国家科技重大专项课题[2017ZX09301025]。

摘　　要：目的测定牡荆素的解离常数(pKa)。方法采用电导法测定电导率(κ),以科尔劳乌施经验公式计算无限稀释下苯酚钠的摩尔电导率(∧m∞)。结果30℃牡荆素的电离平衡常数(K)为8.77×10^-10。结论氯化钠溶液用于临床配制药物,pH为8.3时,85%的牡荆素以分子形式存在。Objective To determine the dissociation constant(pKa)of vitexin.Methods Conductance method was used to determine the conductivity(κ),and Kohlrausch’s empirical formula was used to calculate the molar conductivity(∧m∞)of sodium phenolate under unlimited equilibrium release.Results The ionization equilibrium constant(K)of vitexin at 30℃was 8.77×10^-10.Conclusion In clinical medication,when the pH value of the drug dissolved in sodium chloride solution is 8.3,85%of vitexin exists in molecular form.

关 键 词：牡荆素 电导法 解离常数 摩尔电导率 

分 类 号：R965[医药卫生—药理学] R972[医药卫生—药学]